This application claims priority of Taiwanese application no. 091216484, filed on Oct. 16,2002.
1. Field of the Invention
The invention relates to a bicycle wheel rim, more particularly to a bicycle wheel rim having annular corner reinforcing members at junctions of an annular spoke mounting wall with left and right annular tire retaining walls of an annular rim body.
2. Description of the Related Art
FIG. 1 illustrates a conventional bicycle wheel rim 1 for use with a tire unit that includes an inner tire 11 and an outer tire 12. The bicycle wheel rim 1 includes left and right annular tire retaining walls 13 and an annular spoke mounting wall 14. Each of the tire retaining walls 13 has an inner edge 131 proximate to a central axis (not shown) of the wheel rim 1, and an outer edge 132 distal from the central axis of the wheel rim 1. The spoke mounting wall 14 interconnects the inner edges 131 of the tire retaining walls 13. Spokes 15 (only one is shown) are mounted on the spoke mounting wall 14.
When the bicycle wheel rim 1 is in use, it is normally subjected to forces (F1) parallel to the spoke mounting wall 14, and forces (F2) parallel to the tire retaining walls 13. The forces (F1, F2) that act in different directions can cause the bicycle wheel rim 1 to deform or even break at junctions of the spoke mounting wall 14 with the tire retaining walls 13.
Therefore, the object of the present invention is to provide a bicycle wheel rim having annular corner reinforcing members at junctions of an annular spoke mounting wall with left and right annular tire retaining walls of an annular rim body so as to strengthen the overall construction of the bicycle wheel rim.
According to the present invention, a bicycle wheel rim is adapted for mounting a plurality of spokes thereon, and comprises an annular rim body and left and right annular corner reinforcing members formed integrally with the rim body.
The rim body includes left and right annular tire retaining walls adapted for retaining a bicycle tire therebetween, and an annular spoke mounting wall connected to the tire retaining walls and formed with a plurality of spoke fastening holes therethrough for mounting of the spokes thereon. Each of the tire retaining walls has an inner edge proximate to a central axis of the rim body, an outer edge distal from the central axis of the rim body, and an outer lateral surface that extends between the inner and outer edges, that faces away from the other of the tire retaining walls, and that lies on a first plane. The spoke mounting wall has left and right edges, each of which is connected to the inner edge of a respective one of the tire retaining walls, and a radial inner surface that extends between the left and right edges, that faces toward the central axis of the rim body, and that lies on a second plane.
Each of the corner reinforcing members is formed integrally with the rim body at a junction of a corresponding one of the left and right edges of the spoke mounting wall with the inner edge of the respective one of the tire retaining walls. Each of the corner reinforcing members extends laterally outward relative to the first plane of the outer lateral surface of the respective one of the tire retaining walls, and further extends radially inward relative to the second plane of the radial inner surface of the spoke mounting wall.